I had trouble following this chapter. It makes no sense for when capturing high profile threats to leave them together and unsupervised. Usually you would separate and keep them under watch. It would also be wise to move them somewhere like their HQ, not some random useless tower conveniently placed. The targets fucking fly, no reason to put them so high up, bring them underground if you want to be fancy. And since they have magic that messes with the senses, they should have cast that on the glasses dude as well. Heck, forget it, magic is not even need, cover their eyes and ears and bind their feet too with chains, limit their oxygen intake, sedate them, break their limbs, etc. Magic is dangerous and countermeasures can be developed on the fly, don't let captured elite mages calmly think.
Even in real life, with no powerful magicians going around wrecking shit, high profile criminals and terrorists are treated with much more caution. If they are willing to fight to death even, why not be much rougher with them? When Ubel fought, she was ready to kill, why are her enemies not doing the same? She has value only for interrogation and maybe ransom/exchange at this point.
If I was the emperor, I would restructure that entire organization to be actually effective. Not even random cops are that incompetent. It is unacceptable for elite forces to so unprofessional. This manga has characters like Denken who always calmly analyze the situation and think things thoroughly, is there really nobody in this old prestigious organization in charge of designing procedures and training their personnel? Even guerrilla forces do it, what the fuck?
I also think the author may be taking the Ubel perception thing a bit to far. I think that for her magic to work on materials that she expect it to work on despite any bullshit magical defense layered upon is fine, but shouldn't the restraining magic work? I assume it would have certain principles as for why the restrainment works, maybe it does something physical to the target body, rendering he or she unable to cast magic. By ignoring this, the author is basically ignoring what has been defined before and giving a free pass to any kind of asspull.
"Aha! You punched me, but I think of myself as being someone who can't be punched as my face is too sacred for that, therefore your punch didn't do shit!. All other types of offense don't work too due to my interpretation."
I'm complaining because the author usually does a good job with theses things, but here he slipped.